kind of non-news but some more confirmation from txb forums :
I know it's a forgone conclusion, but MGS is busy working on the next Forza, presumably for the Xbox 360.
Sound engineers (for lack of their proper job title) were out in the Pacific Northwest area recording engine sounds today from some pretty awesome cars.
I'm not sure they got audio from all the cars, but among the sweet rides were a C5 Z06, Ferrari 360 Modena and a Carerra GT.
With any luck, I'll have some photos later, but I thought I'd pass on the news.
There wasn't any doubt that a sequel is coming, but it's still cool to see them actually working on it.
Anyway, when he asked, the Microsoft folks replied they were working on the next Forza. They did not say Forza 2 or Forza 360, simply the next Forza.
Apparently they record engine audio on a dyno, but come out to actual tracks to get more engine sounds in a more real world environment.